The work is concerned with the analysis of psychophysiological data recorded on magnetic tape in 1972/3 as part of a large project on children at 'high risk' for schizophrenia. The data are drawn from two sources. The first is the retesting of the sample from the high-risk study of Mednick and Schulsinger initiated in Copenhagen in 1962. The data on tape are from the sample when at the mean age of 25 and hence well into the risk period for schizophrenia. The second group of data are from a sample of subjects aged 11/12 from a large population whose birth data is very fully recorded and who are the offspring of schizophrenic, character disordered and normal parents. The data comprised recording of skin conductance from left and right hands, skin potential from the left hand, EKG and EEG for left and right occipital placements. Recordings are of tonic levels and phasic responses to standard tape recorded auditory stimuli. After full analysis the data will be examined in the context of the large data bases available in Copenhagen providing obstetric, developmental, social, psychological and psychiatric background of the subjects.